NC State reported on October 7 that a soft underwater robot inspired by feather stars can maneuver in three dimensions using two actuators. Its four flexible wings produce different swimming modes depending on how the actuators are timed: pulsation for vertical movement, asymmetric motion for propulsion, and alternating motion for rotation.
The Science Advances study includes camera exploration and underwater lifting demonstrations. The university identifies a fully wireless version as future work. The result demonstrates a mechanical design and control approach; it does not establish an untethered inspection product ready for field deployment.
NAOAT analysis
The interesting engineering choice is where the coordination happens. Instead of assigning a separate motor to every desired movement, the structure transforms a few inputs into useful patterns. That makes the body part of the controller. A designer evaluating this approach would need to understand both the available movements and the conditions under which one pattern changes into another.
Consider an inspection task that requires approaching a pipe, holding a camera steady and backing away. The fastest swimming mode would answer only one part of that assignment. The more informative demonstration would show transitions between movement and observation while carrying the intended camera. Image stability during those transitions could matter more to the inspection result than speed alone.
The lifting demonstration suggests another question: how does a carried load change the motions produced by the same inputs? A comparison across payload positions could reveal whether the design keeps its simple control scheme or requires substantial retuning. Such tests would connect the elegant mechanism to a specific job. They would also give developers evidence for deciding what belongs onboard in a wireless version. Fewer actuators are an attractive starting point, but the practical benefit depends on the complete package of power, control, sensing and payload that must travel with the robot.